Anyone know a good exercise to stenghthen your fingertips for climbing?l can not use my door frame because it is too weak.Any other suggestions?

Climbing tends to strengthen your fingers. May l suggest bouldering so that you're not tempted to go using every jug you see and get a bit of weight on those digits. Also you can buy a little grip strenthener thing in most sports shops. There is one that is made especailly for climbers called the gripmaster or something look for that.

Get one of these:

http://metoliusclimbing.com/holds_boards_simulator.htm

go to RE l or local outdoor/climbing store. Most climbing sections will have ''stress toys'' for climbing. They do a great job strenthening fore arms, hands, and fingers. They usally cost less than $10 and you can use them while driving, talking on the phone, or anytime!

Campus board, door jamb/finger tip pullups, bouldering.

If ur door jamb is too week, put in a pullup bar in the frame. u could rig a 2x10 to use as a free hanging training board. drill one hole in each corner wide enough to put cord through. Attach the cords to the pullup bar.
The 2x10 board, drill in varius sized & depth holes on each side. Round them/smooth them with sand paper so u do not cut ur tips. If u have a router u could get very creative with the design. then use it like a campus board, or put fingers in various holds, one hand on each side of the board, & either hang or try to pull up!
You can moderate the weight by staning on a chair or something like that.

The campus board or similar (homemade version) apparatus has u hang from different sized pockets or crimps with different finger/finger tip combinations.
Lots of companies make them,
You can vary the amount of weight u have on them by controlling how much weight u put on ur feet/size of foot holds.

The sqeezie things r more for grip strength.

Your door frame is NOT too weak. It just needs a few nails, very thin ''spikes'' will work perfect. If u hit the stud, one on each corner should be all u need for reinforcement. LOL, l have to do the same thing becuase l pried my trim off with my ice tools the other day. l definately fell on my ass!

Otherwise get a hangoard which offers more variety but you're still gonna have to put screws into the doorframe for that.

Remember to use the relaxed ''fingertip'' grip wherever u can, because it is more efficient use of ur energy, but also practice ''crimping'' (bent knuckes) for those tiny holds. You can practice crimping on ur door frames too, just imagine there is only 1cm there to work with.

go climbing. The old addage, the best training for climbing is climbing